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Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthro
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support |
Date: |
Wed, 2 Jul 2014 21:00:00 +0300 |
On Wed, Jul 02, 2014 at 06:29:23PM +0200, Paolo Bonzini wrote:
> Il 02/07/2014 17:27, Michael S. Tsirkin ha scritto:
> > At some level, maybe Paolo is right. Ignore existing drivers and ask
> > intel developers to update their drivers to do something sane on
> > hypervisors, even if they do ugly things on real hardware.
> >
> > A simple proposal since what I wrote earlier though apparently wasn't
> > very clear:
> >
> > Detect Xen subsystem vendor id on vga card.
> > If there, avoid poking at chipset. Instead
> > - use subsystem device # for card type
>
> You mean for PCH type (aka PCH device id).
>
> > - use second half of BAR0 of device
> > - instead of access to pci host
> >
> > hypervisors will simply take BAR0 and double it in size,
> > make second part map to what would be the pci host.
>
> Nice. Detecting the backdoor via the subsystem vendor id
> is clever.
>
> I'm not sure if it's possible to just double the size of BAR0
> or not,
Why won't it be?
You just make one bit that is RO in hw RW in QEMU.
> but my laptop has:
>
> Region 0: Memory at d0000000 (64-bit, non-prefetchable) [size=4M]
> Region 2: Memory at c0000000 (64-bit, prefetchable) [size=256M]
> Region 4: I/O ports at 5000 [size=64]
>
> and I hope we can reserve a few KB for hypervisors within those
> 4M, or 8 bytes for an address/data pair (like cf8/cfc) within BAR4's
> 64 bytes (or grow BAR4 to 128 bytes, or something like that).
Wasting IO isn't a good idea usually.
> Xen can still add the hacky machine type if they want for existing
> hosts, but this would be a nice way forward.
>
> Paolo
We need to get agreement from driver writers though,
specifically windows guys.
--
MST
- [Qemu-devel] ResettRe: [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, (continued)
- Re: [Qemu-devel] ResettRe: [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Konrad Rzeszutek Wilk, 2014/07/02
- Re: [Qemu-devel] ResettRe: [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Paolo Bonzini, 2014/07/02
- Re: [Qemu-devel] ResettRe: [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Michael S. Tsirkin, 2014/07/02
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Ross Philipson, 2014/07/02
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Michael S. Tsirkin, 2014/07/02
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Paolo Bonzini, 2014/07/02
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Konrad Rzeszutek Wilk, 2014/07/02
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support,
Michael S. Tsirkin <=
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Chen, Tiejun, 2014/07/03
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Michael S. Tsirkin, 2014/07/03
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Stefano Stabellini, 2014/07/01
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Michael S. Tsirkin, 2014/07/01
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Chen, Tiejun, 2014/07/01
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Michael S. Tsirkin, 2014/07/02
- Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Chen, Tiejun, 2014/07/02
Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support, Michael S. Tsirkin, 2014/07/01